The present invention relates generally to the field of munitions and to the processes of manufacturing such items. Though our invention, as will be explained later, is applicable elsewhere.
Persons working in the field of munition research and development are continually engaged in the never ending effort to improve munitions both as an article of manufacture and in the manufacturing process therefor. This constant endeavor has brought to fruition the instant invention.
In the past, before the instant invention, orifices, holes and relief areas to be had in case of molded articles were generally made after the molding or casting operations. Boring, drilling, extruding, cutting, etc. were and still are conventional techniques to accomplish this end. To eliminate waste, manufacturing time, etc., alternatively, it is now conventional to cast or mold recesses, holes, cavities, etc., by the use of cores, mandrels, cope and drag arrangements, etc. So also, it is conventional to use high temperature (than the material being worked on) resistant materials as the molds and mandrels. That is, the use of steel as the mold when casting copper or molding plastic, is an example.
All of the above recited techniques of manufacturing articles involving molding and casting steps have serious drawbacks. When making recesses, holes, apertures and the like in finished molded and cast articles as aforementioned, additional manhours and process steps are always required. So also, product costs are high because machining costs such as cutting, drilling, boring, etc. are high. When the recesses, apertures, and holes, are molded or cast in place machining costs are reduced, and casting and molding material is saved because less is utilized. However, mandrels, cores and pins for making same must still be removed. Hence, costs of production, etc. still plagues the casting, molding and pressing article making arts. In each of the above, a finished article made by a molding or casting operation has variations in size and shape due to machine tool wear and variance and due to the many variable associated with molding and casting with mandrels, cores, etc. which must be removed. Heretofore, the sizes and shapes of certain articles have, until the present invention, been dictated by molding techniques and requisites. That is, in order to remove certain of the molding and casting components, such as mandrels, cores, pins, etc. it has been necessary to create tapers and drafts.
Our invention was conceived and reduced to practice to solve the above described problems and to satisfy the long-felt need of producing uniform cast, molded and pressed articles of manufacture at the most economical rate.
Briefly, our invention is a new apertured munition which has either been cast, molded or pressed with a combustible or disposable core or mandrel therein. And a new and unobvious process of molding, casting and pressing during manufacturing of our munition whereby core and mandrel cleaning and removal is eliminated. Hence, our invention is to mold, cast or press an article (having one or more mandrels) to shape and to leave it or them in place until use thereof so that the mandrels can be used to protect it in the storage and shipment of the article. And then in use, the mandrel or mandrels can be removed either during use or preparatory thereto.
A principal object of our invention is to provide an apertured article of manufacture with the apertures either fully or partially closed by molding, casting and pressing mandrels.
Another object of our invention is to provide an apertured, article of manufacture with apertures formed and kept closed at least partially by molding, casting or pressing mandrels until the article is used.
A further object of our invention is to provide an apertured article with mandrel reinforcement kept within the apertures for storage and handling purposes until use.
A still further object of our invention is to provide apertured articles of manufactures with molding, casting or pressing mandrels closing at least partially said apertures for handling until use and said mandrels are removed by environmental factors when the article is placed in use.
Other objects will become more apparent after considering the following description of the invention in conjunction with the accompanying drawings.